Phytophthora infestans is the causal agent of potato late blight, one of the most devastating diseases of potato. In order to gain more insight in the molecular and cellular processes involved in pathogenicity we have isolated P. infesfans genes of which the expression is specifically induced during growth of the pathogen in the host plant. From two of these in planta induced (ipi) genes, ipi1 and ipi02, high levels of mRNA can be detected in infected potato leaves and tubers during the first two days of the infection cycle whereas one day later the ipi0 mRNA level is strongly decreased. In in vitro grown mycelium ipi0 gene expression is induced by nutrient deprivation (Pieterse et al., MGG 244: 269-277). The two ipi0 genes are 98% homologous. The difference between the two proteins, IPI-01 and IPI-02, is limited to four amino acid and there is no homology with any known protein (Pieterse et al., Gene 138: 67-77). Besides a putative signal peptide both proteins contain the tripeptide Arg-Gly-Asp (RGD) which functions as a "cell attachment" sequence in several mammalian proteins. Whether the RGD tripeptide present in IPI-0 has a similar function is unknown. To determine the function of IPI-0, biochemical analysis and immunocytological localization were performed. In addition, P.infestans transformants producing anti-sense ipi0 mRNA were obtained and these were tested for their ability to cause disease on potato leaves. Results of these experiments will be presented and the possible role of IPI-0 during pathogenesis of P.infestans on potato will be discussed.
|Journal||Journal of Cellular Biochemistry|
|Publication status||Published - 1995|